With as auspicious a guest as Kelly Clarkson, you know Jimmy Fallon was going to pull out all the stops. And he did, dueting with Clarkson on an extensive medley that contained pretty much the entire history of pop music.

Apparently still smarting from the last time Josh Hutcherson beat him in a game of beer hockey, Jimmy Fallon challenged the Hunger Games star, 22, to a rematch during his appearance on Friday's episode of The Tonight Show.

Ice T has one of the most distinctive voices in pop culture. And whether you know him more as a rapper or a detective on Law & Order: SVU, you're bound to recognize that iconic rasp, even if it were coming out of, say, a G.I. Joe character.

That was the theory Jimmy Fallon set out to test on Wednesday's Tonight Show, anyway.

Christina Aguilera and Britney Spears have known each other since they were both Mouseketeers on The Mickey Mouse Club back in the early '90s, so it makes sense that Aguilera would have internalized her peer's vocal stylings.

This is the most important thing you'll ever learn about Jamie Dornan.

"I'm totally obsessed with Don Rickles," Dornan revealed to Jimmy Fallon Monday night on The Tonight Show, which is definitely not the celebrity crush we'd've expected the Fifty Shades star to reveal. But his passion for the 88-year-old comic famous for his insults runs deep.